* Add new version property to handle joined version numbers
* Add unit test for new joined property
* Add documentation on version.up_to() and version.joined
Things that accessed the cdd package, such as `spack info cdd run
tripped over a buglet in the *cdd* package, causing them to exit with
something like this:
```
Caused by:
TypeError: 'str' object is not callable
File "/rss/spack/lib/spack/spack/repository.py", line 584, in get
self._instances[key] = package_class(copy)
File "/rss/spack/lib/spack/spack/package.py", line 398, in __init__
f = fs.for_package_version(self, self.version)
File "/rss/spack/lib/spack/spack/fetch_strategy.py", line 852, in for_package_version
attrs['url'] = pkg.url_for_version(version)
File "/rss/spack/var/spack/repos/builtin/packages/cdd/package.py", line 40, in url_for_version
str(version.dotted()).replace('.', ''))
```
@tgamblin pointed out that `dotted` is a property, not a functin call
and that the parentheses are therefor inappropriate.
This deletes the parentheses. `spack info cdd` now works for me.
- use two empty lines before `class`
- change version numbering scheme for packages, use `url_for_version` to make things work
- specify dependency types
- add comment about temporarily moved download location
- update two packages to newer versions
